This invention relates to an antenna and, more particularly, an antenna that can be used to enable low frequency RFID devices carried by animals to be read particularly when the animals are proceeding through a race or the like.
The use of low frequency RFID devices to provide a means of identification of animals is well known. The RFID device is interrogated (read) by a suitable reader that incorporates an antenna.
There are many situations in which such devices need to be read. One is in a stock race through which animals will move.
As with any identification system there is a need to maintain a high level of integrity so as to, for example, ensure that each tagged animal moving through a stock race will have its RFID device read. A problem that can arise in such situations is that the animal may move through too quickly for the RFID device to be read, or can move through the race in such a manner that the RFID device is not detected and read. This is especially so with small animals, such as sheep, where the animals can move rapidly through a race and, furthermore, can move in an unpredictable manner. The latter can result in a RFID device not being read due to the animal moving through a null zone in the antenna.
A solution to this problem is to ensure that animals moving through the race are held at some point in the race so that the RFID device can be read whereupon the animal is then allowed to move through the race. This, however, can be difficult for a variety of reasons but, in any event, does result in the procedure of moving the animals through the race and the reading of the RFID devices to be a more time consuming and tedious process than is desired.